Disinfecting process



' 50 2. Because of its toxicity,

gas must be forcibly expelled from the chambers Patented 4, 1939 William H. Engels, ltahway, N. .L, assignor to Merck & 00., Inc, Railway, 1., a corporation of New Jersey No Drawing.

Application February 14, 1935, Serial No. 6,483

t Claims. (01. 21-58) This invention relates to an improved method of disinfecting incubators or hatchers.

More particularly, it is concerned with a method for disinfecting incubating devices for 5 hen eggs, whereby the spread of white'diarrhea among chickens may be controlled orprevented.

This disease is caused by the organism Salmonella pullorum which, it is'generally understood, is transmitted from the mother hen to the egg. The

10 general purpose of the invention is to prevent the chicks which as embryos have suilered contamination from communicating the infection to' healthy chicks which are hatched simultaneously with the infected birds. It is generally believed l5 that in the incubator or hatcher the infection is most frequently transmitted to the uninfected chicks by breathing of contaminated debris (such as chicken down, droppings, etc.) which is blown about the incubator by the forced air circulating 20 system generally forming part of the device and c it therefore, essential to continuously sterilize the incubator contents during the hatching period.

Themethod at presentemployed for this pur- 25 pose'consists in placing within the hatcher or incubator a mixture of a 30 to 40% formaldehyde solution (prepared in accordance with U. S. P. standards) and potassium permanganate. This mixture releases formaldehyde gas which exer- 30. cises bactericidal action upon the incubator or hatcher contents. This method possesses the following serious disadvantages, however, which render it unsatisfactory:

1. The formaldehyde is toxic to' the onions, if '35 absorbed by them in relatively large quantities and, therefore, careful admeasurement and control of the amounts placed in the hatcher are v necessary in order to avoid an overcharge. Such precise admeasurement is diflicult, since the com- 40 mercial formaldehyde solution practically available. at the hatchery will vary" in strength; the amount of gas liberated through the action of the potassium permanganate is not evolved at a constant rate throughout the entire reaction I45 period during any one treatment or successive treatments. Thus, even when identical ingredicuts and quantities are successively used, the

amount of gas evolved will often vary as-much as 50% more or less.

the formaldehyde of the hatchery after a short period, generally after approximately 10 minutes, and it is then necessary' tc permit some time to elapse before 65 re-charging the chambers with the formaldehyde. In fact, the treatment is generally not repeated more than two or three times during an entire hatching period. Thus, it will'be seen that by this method, the chambers are not in sterile condition during the greater part of the hatch- 5 ing period.

It is, therefore, the prime object of the present invention to carry out a continuously effective disinfection process of the type described, without the necessity of renewing the bactericides, 10"

and without harmful effect on the chicks.

I have found that this object may be accomplished by maintaining the atmosphere of the hatchery chambers completely saturated with a disinfecting agent which may be used in a quantity sufliciently large to exert'a constant bactericidal action throughout the hatching of an entire brood, without untoward effect on the chicks.

According to my invention, I place within the hatcher or incubator a quantity of a bactericidal material which, by its inherent vapor pressure,

' will readily volatilize within the temperature range of 96 F. to 104 F., the range usually maintained in incubating devices of the type described,

in suflicient quantity to destroy the germs efliciently and yet, at the same time, remain innocuous to the healthy birds. Thevapors thus volatilized in sufficient concentration will disinfect Y the hatcher, generally, and particularly the'down of the newly hatched infected birds, so that even if the down is blown about the chambers, after drying,-the other-birds, will not contract the disease from it. e

I have now found that chlorthymol, for in stance,-satisfactorily meets the requirements of -my purpose, since it rapidly vol'atilizes and, at

the temperatures required for incubators and 'hatchers, its maximum vapor concentration will be non-toxic. V V V In practicing my invention I expose to the air circulating in the hatchery chamber a quantity of a'dislnfectant of the type described, in dry crystalline form. The disinfectant volatilizes from the crystals until a state of equilibrium is established between its-vapor pressure and the concentration of thevapor of the circulating air. Also, in order to secure the largest surfaceexposure possible, and thereby shorten the time required for the saturation point to be reached,

it is desirable to present the crystals, to the air of the chambers in the most finely powdered form possible. V J

The amount of disinfectant used should be in excess of that actuallyrequired, and should be governed by the size of the apparatus to be used. an

For example, in disinfecting a' forced. draft hatcher of approximately 100 cu. feet in size, the procedure and admeasurements are as follows:

A rack comprising six cloth-spanned frames about 20"x20"' is placed in the compartment containing the air-circulating and humidifying system, the rack being positioned as closely as possible to the air circulatingfan. About one pound of flnely powdered chlorthymol is then spread out widely over the cloth spanning the frames. By the action of the air circulating throughout the hatcher, the disinfectant material will volatilize more or less rapidly, according to the degree of surface exposure attained, and thoroughlydisinfect the hatcher contents. The

, time required for exposure is about three days, 36

hatching,chambers. As a matter of fact, the

amount of chlorthymol actually consumed under the conditions described is only about one ounce. Although I have specifically mentioned chlor thymol as being eminently suitable for use in my method, other materials-of similar character may be used, it being understood that in order to be effective, such material must be capable of vole-- tilization under the conditions of the required temperature and humidity and capable of being used in such quantity as is required for constant disinfecting action; and it must, of course, also be non-toxic to the new-born birds at incubator and hatcher temperature.

I claim as my invention:

1. A method of continuously and uniformly disinfecting the contents of hatchery chambers which comprises exposing to the air circulating in said chambers an amount of crystalline chlorthymol in excess of the amount actually required for disinfecting purposes, said disinfectant being readily volatile under the temperature and humidity conditions maintainedin incubators and hatchers, and maintaining a substantially constant amount of said chlorthymol in the vapor phase within said chambers.

2. The method of disinfecting hatchers and incubators which consists of placing within the chambers thereof and under the influence of the circulating and humidifying system a receptacle containing an excess of finely ground crystalline chlorthymol to give the maximum surface exposure for the rapid and continued volatilization.

of the said chlorthymol to saturate the air in the system under the conditions of temperature and humidity of such devices, and continuing the treatment throughout the hatching period of an entire brood.

3. A method for protecting newly incubatorborn chicks against the attack of the organism Salmonella pullorum which comprises disinfecting the contents of incubating devices by continuously maintaining the air of such devices impregnated with vaporous chlorthymol by-ex'- posing to the air an amount of chlorthymol in excess of that required for impregnation under the temperature and humidity conditions maintained in incubators and hatchers. v

4; A method of protecting newly incubatorborn fowl against attack by disease germs, especially of the order of Salmonella pullo'rum, which comprises impregnating the hatcher atmosphere with chlorthymol in its vapor phase at a substantially constant equilibrium.

5. A method for protecting newlyincubatorborn chicks against the disease white diarrhea which comprises disinfecting the contents of incubating devices by continuously maintaining the air therein impregnated with vaporous chlorthymol, by exposing to the air an amount of chlorthymol approximately equivalent to one ounce per 100 cubic feet of air space.

6. A'method for protecting newly incubatorborn chicks against the disease white diarrhea which comprises disinfecting the contents of incubating devices by continuously maintaining the air therein impregnated with vaporous chlorthymol, by exposing to the air an'amount of finely divided crystalline chlorthymol in excess of one ounce per 100 cubic feet of air space within the apparatus.

' WILLIAM H. ENGELS. 

